Carbon Fiber Composites Recycling Technology Enabled by the TuFF Technology

Abstract

Carbon Fiber Composites (CFCs) recycling has received increasing interest by the composites industry, but it is still in its early stages as an industry. There are two primary challenges that need to be addressed in order to achieve full property retention during CFC recycling: (1) the ability to recover the fiber content without property loss; and (2) conversion of the recycled, short fiber material back into high-performance CFC structures. The ability to manufacture high fiber volume fraction CFCs with end-of-life products would provide an opportunity to reduce material cost and lifetime-embodied energy. In this paper, recycled, short carbon fibers are processed via solvolysis and converted into high-performance CFCs with fiber volume fraction of ~50% and excellent composite property retention. This is enabled through alignment of the discontinuous, recycled fiber feedstock using the Tailorable universal Feedstock for Forming (TuFF) process. The paper introduces the necessary steps to process the fibers in the wet-laid process and explores the resulting mechanical and microstructural properties. The importance of incoming fiber surface quality and the effect of surface contamination from residue left by the recycling process on both the TuFF process and final composite properties is discussed in detail. A pyrolytic process has been adopted to remove the residue that is a by-product of the recycling process from the incoming recycled fiber surface. The approach presents a promising pathway for the recycling of high-performance CFCs.